# Increase MongoDB Cluster Shards

DBaaS allows you to increase the number of shards for MongoDB Enterprise sharded clusters. An increased shard count increases the overall storage of the cluster.

{% hint style="info" %}
**Note:** We recommend you to review the [<mark style="color:blue;">Considerations</mark>](https://www.mongodb.com/docs/manual/tutorial/add-shards-to-shard-cluster/#considerations) before adding shards.
{% endhint %}

To increase the number of shards, send a `PATCH` request with the new `shards` count.

## Endpoint

Use the following endpoint to request the new instances count: `https://api.ionos.com/databases/mongodb/clusters/{clusterId}`

{% hint style="info" %}
**Note:**

* The sample cluster UUID is `d02de413-d5af-4104-a6f9-3a3c2766ee61`.
* You can increase the number of shards to a maximum of 100.
  {% endhint %}

## Request

```bash
curl --include \
    --request PATCH \
    --user "clientname@ionos.com:Mb2.r5oHf-0t" \
    --header "Content-Type: application/json" \
    --data-binary '{
      "properties": {
        "shards": 3
      }
    }' 
```

## Response

```json
{
  "type": "cluster",
  "id": "d02de413-d5af-4104-a6f9-3a3c2766ee61",
  "metadata": {
    "state": "BUSY",
    "health": "HEALTHY",
    "createdDate": "2020-12-10T12:37:50.000Z",
    "createdBy": "clientname@ionos.com",
    "createdByUserId": "012342f-411f-1eeb-9d07-046c59cc737e"
  },
  "properties": {
    "displayName": "Represents database name",
    "location": "de/fkb",
    "connections": [
      {
        "datacenterId": "b72ebcf5-6158-4ddb-8f65-31b20d82b6c7",
        "lanId": "2",
        "cidrList": [
          "10.1.1.3/24",
          "10.1.1.4/24",
          "10.1.1.5/24"
        ]
      }
    ],
    "mongoDBVersion": "6.0",
    "instances": 3,
    "maintenanceWindow": {
      "dayOfTheWeek": "Thursday",
      "time": "08:53:15"
    },
    "connectionString": "mongodb+srv://m-65f4a879f126e3c4.mongodb.de-fra.ionos.com",
    "backup": {},
    "edition": "enterprise",
    "cores": 1,
    "ram": 2048,
    "storageSize": 10240,
    "storageType": "SSD Standard",
    "shards": 3,
    "biConnector": {
      "enabled": false
    },
    "type": "sharded-cluster"
  }
}
```

The `PATCH` example modifies a previously created sharded cluster and sets the number of shards to three.

New shards added this way are created by provisioning new servers and adding them to the sharded cluster. Each shard has the number of servers provided by the instances field. Sharded collections' data will then be distributed to the new shards. For more information, see [<mark style="color:blue;">Balancer Internals</mark>](https://www.mongodb.com/docs/manual/core/sharding-balancer-administration/#std-label-sharding-internals-balancing).

{% hint style="info" %}
**Note:** Decreasing shards is currently not possible.
{% endhint %}